import java.util.Scanner;
//DP34 【模板】前缀和
public class Solution1 {
        public static void main(String[] args) {
            Scanner in = new Scanner(System.in);
            int n = in.nextInt();
            int q = in.nextInt();
            int[] arr = new int[n+1];
            for (int i = 1; i < n+1; i++) {
                arr[i] = in.nextInt();
            }
            long[] dp = new long[n+1];
            for (int i = 1; i < n+1; i++) {
                dp[i] = dp[i-1] + arr[i];
            }

            while (q > 0) {
                int l = in.nextInt();
                int r = in.nextInt();
                System.out.println(dp[r] - dp[l-1]);
                q--;
            }
        }
}
